Method of alkylating cyclic non-aromatic hydrocarbons



United States Patent 3,338,908 METHOD OF ALKYLATING CYCLIC NON-AROMATIC HYDROCARBONS Raymond A. Franz, Kirkwood, and Ronald 0. Downs,

St. Louis, Mo., assiguors to Monsanto Chemical Company, St. Louis, Mo., a corporation of Delaware No Drawing. Filed Dec. 23, 1963, Ser. No. 332,958 16 Claims. (Cl. 260293) The present invention relates to a process for the alkylation of cyclic nonaromatic compounds. More particularly, the present invention relates to the condensation of an unsaturated aliphatic hydrocarbon with a cyclic nonaromatic compound to produce alkyl substituted cyclic nonaromatic compounds.

To thermally alkylate cyclic nonaromatic compounds, particularly naphthenic hydrocarbons, by the condensation of an unsaturated hydrocarbon such as a mono-olefin with a naphthene has been suggested by the prior art. However, by the process of the prior art, the conversions obtained have been somewhat less than satisfactory. Longer residence times have been shown to produce somewhat greater conversions. Even with longer residence times, however, the conversions obtained by the thermal alkylation of naphthenes with unsaturated mono-olefins by the process of the prior art are still far too low for commercial acceptance.

It is an object of the present invention to provide a new and improved process for the alkylation of cyclic nonaromatic compounds. Another object of the present invention is to provide a new and improved process for the alkylation of cyclic nonaromatic compounds by condensation -of unsaturated aliphatic hydrocarbons with cyclic nonaromatic compounds. It is another object of the present invention to provide a new and novel noncatalytic thermal alkylation process for the thermal alkylation of cyclic nonaromatic compounds with unsaturated aliphatic hydrocarbons. Additional objects of the present invention will become apparent from the following description of the invention herein disclosed.

In fulfillment of these and other objects, it has been found that vastly improved conversions may be obtained in the alkylation of cyclic nonaromatic compounds by condensation of unsaturated aliphatic hydrocarbons with cyclic nonaromatic compounds if the alkylation is carried out at elevated temperatures and pressures in a thermal reaction zone in the presence of a minor amount of a modifying agent selected from the group consisting of H S, HCl, HBr, HI and combinations thereof and compounds and elements which under the conditions of temperature and pressure of the reaction zone will produce a compound selected from the group consisting of H 8, HCl, HBr, HI and combinations thereof. This thermal alkylation process produces significantly improved conversions from the condensation of unsaturated aliphatic hydrocarbons with cyclic nonaromatic compounds as compared to the same reaction carried out under thermal reaction conditions without the use of the elevated pressures, temperatures, and the modifying agents of the present invention.

The phrase unsaturated aliphatic hydrocarbon as used-herein refers to either straight-chain or branchedchain aliphatic hydrocarbons which are monoor polyethylenically unsaturated and also acetylenically unsaturated.

The phrase cyclic nonaromatic'compounds as used herein refers to cyclic compounds either saturated or unsaturated, both monoand poly-cyclic, which are nonaromatic. For example, cyclopentane, cyclopentene, cyclopentadiene are within the meaning of the phrase.

In order to further describe and to demonstrate the present invention, the following examples are presented.

These examples are in no way to be construed as limiting the present invention.

Example I Approximately 5 grams of methylcyclopentane, 0.25 gram of propylene and 0.05 gram of benzenethiol were charged to a stainless steel reaction tube having a capacity of 22 ml. The reaction chamber was 12 inches in length and had a diameter of V2 inch. The thermal reaction chamberwas sealed and placed in a vertical electrical furnace and heated to 400 C. at which temperature it was maintained for approximately 30 minutes. After this heating period the reaction mass was cooled and the unreacted gas vented. The product obtained weighed approximately 5.1 grams. Analysis of the product showed a conversion of 12.9 percent based on the propylene charged. The alkylated product was l-methyl-l-n-propylcyclopentane.

Example II Example III Example I was again substantially repeated with the exception that the reaction time period was approximately 160 minutes. A conversion to alkylate of approximately 44.6 percent was obtained. The alkylated product was 1-methyl-1-n-propylcyclopentane.

Example IV Example III was repeated with the exception that no benzenethiol or other modifying agent was added. A conversion of 20.5 percent was obtained. The alkylated product was l-methyl-l-n-propylcyclopentane.

Comparison of the runs of Example III and Example IV again clearly demonstrates the vastly improved results obtainable with the present invention. Example III which illustrates the present invention shows an increase in conversion of approximately percent over that of Example IV which is in accordance with the prior art.

The following examples are presented to illustrate the utility of other modifying agents.

Example V Example I is substantially repeated with the exception that the modifying agent is thiourea. A high conversion to l-methyl-l-n-propylcyclopentane is obtained.

Example VI Example I is substantially repeated with the exception that the modifying agent is elemental sulfur. A high conversion to 1-methyl-l-n-propylcyclopentane is obtained.

Example VII Example I is substantially repeated with the exception that the modifying agent is hydrogen sulfide. A high conversion to l-methyl-l-n-propylcyclopentane is obtained.

Example VIII Example I is substantially repeated with the exception I that the modifying agent is bromopropane. A high conversion to l-methyl-l-n-propylcyclopentane is obtained.

23 Example IX Example I is substantially repeated with the exception that the modifying agent is chlorobenzene. A high conversion to l-rnethyl-l-n-propylcyclopentane is obtained.

Example X Example I is substantially repeated with the exception that the modifying agent is hydrogen bromide. A high conversion to l-methyl-l-n-propylcyclopentane is obtained.

Example XI Example I is substantially repeated with the exception that the modifying agent is Z-methyl-Z-butanethiol. A high conversion to l-methyl-l-n-propylcyclopentane is obtained.

The cyclic nonaromatic compounds which may be alkylated in accordance with the process of the present invention are those monoand polycyclic compounds which are nonaromatic and includes cyclo-paraffins, cyclo-olefins, and cyclo-polyolefins. Several non-limiting examples of compounds within this classification are cyclobutane, cyclopentane, cyclohexane, cycloheptane, cycle-octane, cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclo-octene, cyclopentadiene, cyclobutadiene, cyclohexadiene, cycloheptadiene, cyclo-octadiene, methylcyclobutane, methylcyclopentane, methylcyclohexane, methylcycloheptane, methylcyclo-octane, methylcyclobutene, methylcyclopentene, methylcycloheptene, methylcyclohexene, methylcyclo-octene, methylcyclopentadiene, methylcyclobutadiene, methylcyclohexadiene, methylcycloheptadiene, methylcyclo-octadiene, ethylcyclobutane, ethylcyclopentane, ethylcyclohexane, ethylcyclo-octene, ethylcycloheptadiene, ethylcyclo-octadiene, methylethylcyclobutane, methylethylcyclo-octane, methylethylcyclopentadiene, ethylcycloheptane, hexylcyclohexane, hexylcyclo-octane, hexylcyclopentadiene, hexylcyclobutadiene, pentylcyclohexane, pentylcyclo-octane, pentylcyclobutadiene, pentylcycloheptadiene, methylpentylcyclobutane, methylpentylcycloheptane, methylpentylcyclohexene, methylpentylcyolo-octadiene, dimethylcyclopentane, dirnethylcyclopentene, dirnethylcyclobutadiene, dimethylcycloheptadiene, diethylcycloheptane, diethylcyclooctane, diethylcyclobutadiene, diethylcyclohexadiene, di-cyclohexane, methyldicyclohexane, decalin, alkyl decalins, octahydroindene, and the like.

Most often, the cyclic nonaromatic compounds will contain 3 to 12 carbon atoms. However, it is preferred that the cyclic nonaromatic compounds have 4 to 10 carbon atoms per molecule. The cyclic nonaromatic compounds operable in the present invention are not limited to those containing only carbon and hydrogen and includes cyclic nonaromatic compounds containing substituents other than carbon within the cyclic ring structure. For, example, such compounds as dihydroor tetrahydrofuran, pyran, as well as their alkyl derivatives, alkyl piperidines, and the like may be alkylated in accordance with the present invention. The cyclic nonaromatic compounds of the present invention may also contain substituents to the ring other than carbon and hydrogen. For example, cyclohexylamines, cyclohexyl ethers, cyclohexyl chlorides, and the like are within the scope 'of the compounds alkylatable by the process of the present invention. In the preferred practice of the present invention, however, the cyclic nonaromatic compounds are cyclic nonaromatic hydrocarbons. Usually, it is preferred that these cyclic nonaromatic hydrocarbons contain at least one tertiary hydrogen atom. Tertiary hydrogen atom, as used herein, refers to a hydrogen attached to a tertiary carbon atom. Thus, preferred compounds alkalatable in accordance with the present invention are the cyclic nonaromatic hydrocarbons containing at least one substituent to one of the carbon atoms of the ring. Most often, this substituent will be an alkyl radical of 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms.

The unsaturated aliphatic hydrocarbons which may be condensed with cyclic nonaromatic compounds according to the process of the present invention comprises organic hydrocarbons containing an ethylenic group and organic hydrocarbons containing an acetylenic group. The ethylenic group of organic hydrocarbons, for the purposes of the present invention, include mono-olefins, di-olefins, triolefins, etc. Several nonlirniting examples of unsaturated aliphatic hydrocarbons suitable for use in the present process are ethylene, propylene, l-butene, 2-butene, isobutylene, l-hexene, 2-hexene, l-octene, 3-octene, l-decene, l-dodecene, 2-dodecene, etc., and acetylenic hydrocarbons such as acetylene, methylacetylene, and the like. The preferred unsaturated hydrocarbons for the purposes of the present invention are the mono-olefin hydrocarbons of 2 to 15 carbon atoms, either straight or branched chain and having either terminal or internal unsaturation.

The mole ratio of the cyclic nonaromatic compound to the unsaturated aliphatic hydrocarbon may vary considerably in the present invention. Generally, rnole ratios of cyclic nonaromatic compound to unsaturated hydrocarbon of 1:1 to 20:1 are used. It is preferred, however primarily for economic reasons, to operate the present invention using a mole ratio of cyclic nonaromatic compound to unsaturated aliphatic hydrocarbon of 3:1 to 15:1.

The modifying agents useful in the present invention are H 8, HCl, HBr, HI, or combinations thereof or compounds or elements which under the conditions of the thermal reaction zone will produce H S, HBr, HCl, H1, or combinations thereof. Usually the modifying agent is a compound which will decompose to form one of these compounds. Such compounds include sulfur bearing compounds, halogen bearing compounds and compounds containing both halogen and sulfur atoms. These compounds may be either organic or inorganic and may be of virtually any molecular weight, being limited only by practicality, practicality in this sense referring to ease of handling in the process. If an organic compound is the modifying agent, it may be straight or branched chain or cyclic and aromatic or nonaromatic and saturated or unsaturated. In addition to the halogen or sulfur bearing compounds, elemental sulfur as well as molecular iodine, chlorine, and bromine may be used. Among the list of modifying agents useful in the present invention to pro duce H S in the reaction chamber are the following nonlimiting examples.

Alkyl sulfide Benzyl disulfide Benzoyl disulfide Benzyl sulfide Dibenzyl sulfide 3-methyl-1-butanethiol Tert-octanethiol Butylsulfide Ethanethiol Ethyl disulfide Furfuryl mercaptan l-hexanethiol Isoamyl sulfide Methyl disulfide Z-naphthalenethiol l-pentanethiol l-propanethiol 2-propanethiol Thiophene Benzenesulfonic acid p-Bromo-benzenesulfonic acid o-Formyl-benzenesulfonic acid Benzyl sulfoxide Butyl sulfate Butyl sulfoxide Thiol-carbamic acid Trithio-carbonic acid Cetyl sulfate 1,2-ethanedisulfonic acid Ethyl sulfoxide Methanethiol ,8,,B'-Dichloroethyl sulfide 2-chlorothiophene 2,5-diiodothiophene Vinyl sulfide Methyl sulfate Dichlorophenylphosphine sulfide Methyl sulfone Ethyl methyl sulfide Dithio-carbonic acid Dodecyl sulfate Ethionic anhydride Ethyl sulfone Ethyl sulfuric acid Methyl sulfoxide 2-bromothiophene 2,5-dibromothiophene 2,3-dimethylthiophene l-decanol sulfate Methyl sulfite Octyl sulfate Bis- (fi-dichloroethyl sulfide Tetradecyl sulfate Thionaphthene Thionaphthenequinone 2-methylthiophene Thiourea o-Toluenethiol Elemental sulfur Benzenethiol Sulfur dissolved in dialkyl alkanol amines I Among the modifynig agents useful in the present invention to produce either HCl, 'HBr, HI, or combinations thereof are the following non-limiting examples.

m-Bromo-chlorobenzene p-Bromo-chlorobenzene Z-bromonaphthalene l-chloronaphthalene 1,3-dichloronaphth'alene 2-bromodiphenyl 2-chl'orodiphenyl Chloroethanoic acid Dibromoethanoic acid Di-iodoethanoic acid a-Chloroacetamide a-Bromoacetanilide Benzoyl chloride Benzoyl bromide Benzoyl iodide Butanoyl chloride Butanoyl bromide Butanoyl iodide 2-chloro-l,4-benzenediol 2-bromo-l,4-benzenediol l-chloro-4-nitronaphthalene o-Bromotoluene Succinyl chloride 4-chloroquinoline Ethanoyl iodide Hexanoyl chloride Decanoyl chloride 2-bromoethanol 2-chloroethanol Bis-,B-chloroethylether Chloromethoxy methane Cyclohexylchloride Cyclohexylbromide l-bromododecane Hydrogen chloride Hydrogen bromide Hydrogen iodide 4-chlorodiphenyl 2-brornopropane 2-chloropropane l-iodopropane l-bromobutane l-chlorobutane Z-iodobutane l-bromopentane Z-bromopentane 3-chloropentane Z-iodopentane 3 -bromohexane 2-bromohexane 2-iodohexane 2-bromo-4-methylhexane 3 -chloroheptane 3-bromoheptane 2-iodoheptane r 2-bromo-4-ethylhexane 4-bromooctane 3-chlorooctane 2-iodooctane l bromononane 2-chlorodecane 2-bromodecane 2-bromo-6-methyl'decane 3 ,3-bromomethyldecane 4-iodoundecane Bromobenzene Chlorobenzene m-Dichlorobenzene o-Dichlorobenzene p-Dichlorobenzene m-Dibromobenzene o-Dibromobenzene p-Dibromobenzene Iodobenzene o-Iodotoluene m-Iodotoluene p-Iodotolnene rine o-Chl'orotoluene Brornme m-Chlorotoluene me Carbon tetrachloride 2-chloro-3 -heXane 2-bromo-2-pentene 3 -bromo-4-octene p-Chlorotoluene m-Bromotoluene p-Bromotoluene 1,3 ,5 -dibromotoluene o-Bromo-chlorobenzene rine, bromine or iodine, as carbon, hydrogen, oxygen, nitrogen, etc. Among the most useful modifying agents of the present invention which produce hydrogen sulfide under the conditions of the thermal reaction zone are elemental sulfur and such sulfur bearing compounds as mercap-tans or thiols, both aliphatic and aromatic, hydrogen sulfide, thioethers, and thioureas. Also within this list of useful hydrogen sulfide producing compounds are those derived by dissolving sulfur in tertiary amines at elevated temperatures as is taught and claimed in co-pending application Ser. No. 148,903, filed Oct. 31, 1961 now US. Patent 3,207,798. A particularly useful group of sulfur modifying agents are elemental sulfur and sulfur bearing compounds containing the additional elements of carbon and/ or hydrogen and/ or nitrogen. When using sulfur bearing compounds containing carbon, it is generally preferred that they contain no greater than 20 carbon atoms.

The halogen modifying agents of the present invention include compounds containing one of the halogens, bromine, chlorine, or iodine, as well as hydrogen halides, HBr, HCl, and HI and the molecular halogens C1 Br and I The most useful halogen containing modifying agents are those which contain one of the above defined halogens and the elements hydrogen and/ or carbon. These compounds are the halogen substituted hydrocarbons and hydrogen halides. Preferably, if halogen substituted hydrocarbons are used, they are monoor di-halogen substi tuted hydrocarbons of no more than 8 carbon atoms. Usually, it is preferred that the halogen used be either chlorine or bromine, with bromine being preferred over chlorine. In the preferred practice of the present invention, the modifying agent used will be one which will decompose to or otherwise form hydrogen sulfide.

The modifying agents useful in the present invention are used in non-catalytic amounts based on the ratio of the hydrogen sulfide, hydrogen chloride, hydrogen bromide, or hydrogen iodide obtainable from the modifying agent to the amount of cyclic nonaromatic compound. Generally, the mole ratio between the amount of hydrogen sulfide, hydrogen chloride, hydrogen bromide, or hydrogen iodide present and the amount of cyclic nonaromatic compound in the feed will be maintained within the range of 0.001:1 to 2:1. Usually this ratio will be within the range of 0.005 :1 to 0.5: 1. It is preferred, however, that the mole ratio of the gas to the cyclic nonaromatic compound be maintained within the range of 0.01 :1 to 0.221.

The condensation of unsaturated hydrocarbons with cyclic nonaromatic compounds according to the present invention is carried out at elevated temperatures, usually within the range of 250 C. to the cracking temperature of the particular hydrocarbons in the feed. The preferred temperatures for operating the present invention are, however, Within the range of from about 300 to 550 C. With the preferred cyclic nona-romatic compounds, temperatures of 350 to 450 C. are generally preferred.

The process disclosed herein is operated at elevated pressures, generally at a pressure of greater than 500 p.s.i.g. The upper limit for pressures for carrying out the present invention is limited only by the strength of the reaction vessel. The preferred pressures for operating the present process will generally be above approximately 1000 p.s.i.g. and below 5000 p.s.i.g.

The residence time of the reactants in the reaction chamber is not particularly critical to the present invention. Residence times of from 0.5 to 500 minutes in a batch system will generally be adequate. It will be preferred to have residence times on the order of 15 to minutes, however. When using a continuous system,

residence times of as low as 0.5 minute to as high as 20 minutes may be used, with 10 to 15 minutes being preferred. The lower residence times of the continuous process are usually offset by somewhat higher temperatures.

The apparatus which may be used in carrying out the present invention may be of virtually any design. Of

course, it will have to be of such design and materials of construction as to withstand relatively high pressures and temperatures. Its primary requirement is only that it be consistent with good engineering principles.

The products of the present invention are alkyl cyclic nonaromatic compounds. The alkylation process of the present invention generally produces alkylation of the cyclic ring rather than any substituents to the ring. This is clearly illustrated by the foregoing examples in which a propyl radical was attached to a carbon atom of the cyclic ring. It should also be noted from the foregoing examples that preferential selectivety for alkylation with a tertiary carbon atom containing a tertiary hydrogen substituent is exhibited by the present process.

What is claimed is:

1. In a process for producing alkyl-substituted cyclic non-aromatic compounds which comprises the condensation of an ethylenically unsaturated hydrocarbon of 2 to 15 carbon atoms with a cyclic non-aromatic compound selected from a group consisting of carbocyclic non-aromatic hydrocarbons of 3 to 12 carbon atoms and heterocyclic non-aromatic compounds of 5 to 7 carbon atoms in the heterocyclic ring and containing no more than one non-carbon atom in said ring, at an elevated temperature within the range of from 300 to 550 C. and a pressure of greater than 500 p.s.i.g., the mol ratio of cyclic non-aromatic compound to ethylenically unsaturated hydrocarbon being within the range of 1:1 to 20: 1, the improvement which comprises carrying out the condensation reaction in the presence of a modifying agent selected from the group consisting of the compounds H 8, HCl, HBr, HI, combinations thereof and compounds and elements which under the conditions of the condensation reaction zone produce a compound selected from the group consisting of H S, HCl, HBr, HI and combinations thereof, the amount of such modifying agent used being sufficient to produce a mol ratio of a compound selected from the group consisting of H 8, HCl, HBr, HI and combinations thereof within the reaction zone to the cyclic non-aromatic compound of 0.00111 to 2: 1.-

2. The process of claim 1 wherein the cyclic non-aromatic compound is a carbocyclic non-aromatic hydrocarbon selected from the group consisting of cycle paraffins, cyclo olefins, and cycle polyolefins.

3. The process of claim 1 wherein the cyclic nonaromatic compound is a cyclic nonaromatic hydrocarbon containing at least one tertiary carbon atom having a hydrogen atom attached thereto.

4: The process of claim 1 wherein the unsaturated aliphatic hydrocarbon is a mono-olefinic hydrocarbon.

5. The process of claim 1 whereinthe mole ratio of cyclic nonaromatic compound to unsaturated aliphatic hydrocarbon is 3 :1 to 15: 1.

6. The process of claim 1 wherein the modifying agent is one which under the conditions of the reaction zone forms H 5.

7. The process of claim 6 wherein is elemental sulfur.

8. The process of claim 6 wherein the modifying agent is one selected from the group consisting of alphatic thiols and aromatic thiols.

9.'The process of claim 6 wherein the modifying agent is hydrogen sulfide.

10. The process of claim 6 wherein the modifying agent is thiourea.

11. The process of claim 1 wherein the modifying agent is one selected from the group consisting of C1 Br I and combinations thereof.

12. The process of claim 1 wherein the modifying agent is one selected from the group consisting of HBr, HCl, and HI, and combinations thereof.

13. The process of claim 1 wherein the modifying agent is an alkyl halide selected from the group consisting of alkyl chlorides, alkyl bromides, alkyl iodides, and combinations thereof in which the alkyl radical has no greater than 8 carbon atoms.

14. The process of claim 1 wherein the temperature of the reaction is within the range of from 350 C. to

the modifying agent References Cited Fieser et al.: Advanced Organic Chemistry, pp. 256 257, Reinhold, N.Y., 1961.

Theilheimer: Synthetic Methods of Organic Chemistry, vol. 5, Karger, N.Y., 1951, pp. 380-381, reaction 507.

WALTER A. MODANCE, Primary Examiner.

A. D. SPEVACK, Assistant Examiner. 

1. IN A PROCESS FOR PRODUCING ALKYL-SUBSTITUTED CYCLIC NON-AROMATIC COMPOUNDS WHICH COMPRISES THE CONDENSATION OF AN ETHYLENICALLY UNSATURATED HYDROCARBON OF 2 TO 15 CARBON ATOMS WHILE A CYCLIC NON-AROMATIC COMPOUND SELECTED FROM A GROUP CONSISTING OF CARBOCYCLIC NON-ARO MATIC HYDROCARBONS OF 3 TO 12 CARBON ATOMS AND HETEROCYCLIC NON-AROMATIC COMPOUNDS OF 5 TO 7 CARBON ATOMS IN THE HETEROCYCLIC RING AND CONTAINING NO MORE THAN ONE NON-CARBON ATOM IN SAID RING, AT AN ELEVATED TEMPERATURE WITHIN THE RANGE OF FROM 300 TO 550*C. AND A PRESSURE GREATER THAN 500 P.S.I.G. THE MOL RATIO OF CYCLIC NON-AROMATIC COMPOUND TO ETHYLENICALLY UNSATURATED HYDROCARBON BEING WITHIN THE RANGE OF 1:1 TO 20:1, THE IMPROVEMENT WHICH COMPRISES CARRYING OUT THE CONDENSATION REACTION IN THE PRESENCE OF A MODIFYING AGENT SELECTED FROM THE GROUP CONSISTING OF THE COMPOUNDS H2S, HC1, HBR, H1, COMBINATIONS THEREOF AND COMPOUNDS AND ELEMENTS WHICH UNDER THE CONDITIONS OF THE CONDENSATION REACTION ZONE PRODUCE A COMPOUND SELECTED FROM THE GROUP CONSISTING OF H2S, CH1, HBR, H1 AND COMBINATIONS THEREOF, THE AMOUNT OF SUCH MODIFYING AGENT USED BEING SUFFICIENT TO PRODUCE A MOL RATIO OF A COMPOUND SELECTED FROM THE GROUP CONSISTING OF H2S, HC1, HBR, H1 AND COMBINATIONS THEREOF WITHIN THE REACTION ZONE TO THE CYCLIC NON-AROMATIC COMPOUND OF 0.001:1 TO 2:1. 